Abstract: TH-PO801
Fast Molecular Profiling of Kidney Biopsy Tissue by Gene Profiling from Biopsy Transport Medium
Session Information
- Pathology and Lab Medicine - I
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1800 Pathology and Lab Medicine
Authors
- Li, Ziyang, Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
- Bruijn, Jan A., Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
- Baelde, Hans J., Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
- Kers, Jesper, Leids Universitair Medisch Centrum, Leiden, Zuid-Holland, Netherlands
Background
Molecular assessment by targeted gene profiling of kidney biopsy tissues is gaining traction in kidney pathology, particularly kidney transplant biopsies (e.g. with the Nanostring B-HOT panel). A critical downside of molecular assessment from FFPE tissues is its turnaround time and same-day diagnostics is currently not feasible. Timely and tailored treatment requires the support of faster and more sensitive molecular assessment and we therefore studied the use of biopsy transport medium (BTM) used to transfer kidney biopsies from the clinic to the pathology ward.
Methods
We utilized tumor-free tissues from complete nephrectomy to cut tissues into small strips, imitating the size of a renal biopsy. These biopsies were stored in PBS to mimic the process of biopsies transport at our department. We optimized RNA isolation by comparing different RNA isolation methods, centrifuge speeds, and storage times of the biopsies in the BTM. We checked the quantity and integrity of the RNA and performed qPCR with different biomarkers. We validate the reliability of BTM by comparing gene expression in BTM and frozen tissues from the same kidney. Finally, from a cohort of regular biopsies, RNA was isolated.
Results
Our results showed that different RNA isolation methods, centrifuge speeds, and different storage time up to 24 hours did not have a significant effect on RNA quality and yield. In a preliminary assessment, we were able to measure cell-specific genes by RT-PCR, representing T cells, B cells, macrophages, and even podocytes. The average RNA yield from regular biopsies was 165ng with RIN values around 7. As an example, CD68 expression of BTM correlated with the CD68 expression of tissue from their corresponding kidneys (N=5, r= 0.902, p<0.05).
Conclusion
Our results demonstrate that we can obtain relatively large amounts of RNA with sufficient quality from BTM, and that gene expression analysis from BTM is practically feasible as we were able to measure the expression levels of cell-specific genes within 5 hours after arrival. BTM represents an interesting new source for rapid molecular assessment and a potentially feasible alternative to molecular assessment on FFPE tissues without the need for an extra biopsy core. Further research should validate its potential in discriminating clinically relevant diagnosis and/or quantification of disease activity.